BOOK 1: THE APPROACH TO THE CATEGORICAL IMPERATIVE -- The critical method -- The good will -- Duty -- The maxim of morality -- Reverence -- The law -- Misunderstandings -- BOOK 2: THE BACKGROUND OF THE CATEGORICAL IMPERATIVE -- Practical reason and its subjective principles -- Practical reason and its objective principles -- The good -- Imperatives -- How are imperatives possible? -- BOOK III: THE FORMULATION OF THE CATEGORICAL IMPERATIVE -- The five formulas -- The formula of universal law -- The formula of the law of nature -- The formula of the end in itself -- The formula of autonomy -- The formula of the kingdom of ends -- BOOK IV: THE JUSTIFICATION OF THE CATEGORICAL IMPERATIVE -- The problem -- Freedom and autonomy -- Freedom as a necessary presupposition -- The intelligible world -- Membership of the intelligible world -- How is a categorical imperative possible? -- Some further questions -- The defence of freedom.